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Prof. Maria PapadopouliUniversity of Crete

ICS-FORTHhttp://www.ics.forth.gr/mobile

Lectures on Wireless Networks & Mobile ComputingDynamic Spectrum Access & Spectrum Markets

CS 439

References & Acknowledgement

The slides of this lecture are heavily based on the • talks given @ IEEE DySPAN’11• IEEE DySPAN’11, Tutorial 5, given by Randall Berry &

Michael Honig, EECS, Northwester University

Spectrum and Cognitive Radios Markets

Dialogue between network operators, manufacturers, federal states & municipalities, and researchers

Broadband & Spectrum Markets

Broadband connections 2001-2010

• The competition among providers has increased substantially

• Interoperability among different types of devices is an important aspect

• Harmonization of CPC frequency allocations in Europe• Specification of access products relevant to mass markets• Conjecture “Cooper’s Law”: spectrum use is doubling every 30

months– Spectrum use: amount of traffic put in the spectrum

Advances on Spectrum

• More spectrum x 25• Thinner slides x 5• Modulation technology x 5• Architecture x 1600

Challenges in cognitive radio evolution:• Complexity of the existing use of spectrum (legacy systems)

Spectrum Markets• Different bands of the spectrum have different value in the market

Large variations in spectrum value in $/MHz/populationGermany ~2Ghz : 0.01 < UK 3G < US 700MHz : 10Two orders of magnitude difference

• Directives on how CR devices can access certified or authorized databases• Cognitive Pilot Channel (CPC)• Support activities for cognitive radios:

– CEPT (SE’43, WGFM), ETSI (e.g., TC-RRS), TCAM, WRC-12, ITU-R• Support corresponding standardization

– ETSI TC-RRS: harmonized standards– CEPT: identify possible candidate band and develop sharing conditions– CEPT ECC Report 159

• Sensing, geo-location and beacon

Spectrum Markets• Business impact of secondary spectrum sharing:

– still unclear– Lots of discussions in the industrial, regulation, policy making, research

& technology sectors• Multi-parameter and utility-based assessment of spectrum value• Consideration of network operators to form “coalitions” for sharing parts a

network infrastructure • Deployment of Femtocells: catalytic of innovation• Lack of transparency in allocation and utilization• Incentive to reallocate spectrum• TV spectrum – utilization of white space in TV spectrum

– Easier to start with– 2 or more stations can combine their

FemtoCell

• A small cellular base station• Typically for use in a home or small business• Connects to the service provider’s network via broadband (e.g., DSL

or cable)• Supports 2 to 4 active mobile phones in a residential setting, and 8 to

16 active mobile phones in enterprise settings• Extends coverage indoors, especially where access would otherwise

be limited or unavailable• Can use WCDMA, GSM, CDMA2000, TD-SCDMA, WiMAX ,LTE• Broadband backhaul introduces issues of network jitter

Spectrum Paradox:• The spectrum is a scarce resource• The spectrum is underutilized!

Dynamic Spectrum Access: Motivation

Two Views on Spectrum Access

Europe vs. US spectrum markets

• Population density52 persons/km2 in Europe, 32 persons/km2 in US

• Europe: many administrators, many borders => need for bilateral agreements

Spectrum Sharing Models

• Exclusive Use• Commons• Hierarchical• Hybrid

Cognitive Radios

Exclusive Use

Spectrum Commons

Hierarchical

Primary & Secondary Users

Hybrid Access Models

Are secondary markets selling?

Current State of Affairs

Companies, such as Microsoft, Google, and British Telecom,express interest in the idea of a geo-database spectrum leasing service